I'm willing to forgive most of it, due to being an SR-71. There's pretty much no way to make a "minimal kibble" transforming SR-71, due to the SR-71 being all area, with no internal volume:
The only way it could ever work is to basically be a combiner of itself---some parts in each nacelle, and the head in the cockpit, then split off those 3 major sections, combine them into a small bot, then try to fold up a bunch of leftover black panels into a backpack. (or somehow have all wing and chine bits separate into individual plates and re-attach to form armor plating around the limbs--cool, but impractical)
(admittedly, the Jetfire toy has nothing in its nacelles AFAIK, and it could have had SOME robot parts stored in them, and not under the belly----could have reduced the kibble at least a bit) Most obvious choice are his thighs--they are his engines, so if the engines were in the nacelles, they wouldn't be hanging under the tailcone in jet mode. Then you could move a bit of the "side" kibble back where they were, and so on.